The LDS have
summarised baptisms and marriages entries for some parish registers, mostly up to 1837 but with entries after that. They have not summarised all parish registers by any means and their coverage varies from parish to parish and from county to county. High in some counties very low in others. They have done it because of their religious beliefs, which do not include finding out any information about burials so they have not looked at parish registers for burials.
Because the IGI does not inlude all baptisms just because a baptism can be found on the IGI does not mean it is the right baptism (or marriage)
There are two sorts of entries on the IGI. Those taken from the actual parish registers (and any transcription may have mistakes in it, you should always if at all possible check the original) and those submitted by LDS church members which can be spot on, or widely inaccurated. The Ancestral files are just the same. In some of these entries you may find mention of death/burial information. These submissions by LDS members must always be checked and taken with a pinch of salt - they could be wrong.
The way to find out cause of death for the later deaths you have in your family tree (after civil registration began) is to purchase the death certificates. In 1885 a burial in Leeds may be in a cemtery or a church, but I doubt it would be any in the city centre. Leeds was a big city so it is going to have more than one cemetery. The record office can tell you who holds the different cemetery records and how to access them and also wwhich churches near to where the death took place where still burying people.
Though the LDS will not have burials on the IGI they will probably hold microfilms of parish registers (but not necessarily up to the period you are interested in). You can order these films to be used at your local LDS for a small cost. They usually take up to a couple of months to arrive. Alternatively you can check out Leeds Record Office.
http://www.archives.wyjs.org.uk/index.asp?pg=vhp.htmlWith interests in Leeds you might also be interested in this website
http://www.leedsindexers.co.uk/A death certificate will also give you an age at death where you don't know it, to help you search for an earlier baptism as for Thomas Ibbetson.
Regards
Valda